Floor-bridging units 10 are used for framing floors of wood buildings. FIG. 1 shows an example of a floor-bridging unit 10. The floor-bridging unit 10 is generally an X shaped member 12 with flanges 14 attached to two sides 16. The floor-bridging units 10 are placed between floor joists 18 and nailed through the flange 14 to the joist 18, as seen in FIG. 2. Once installed in rows between the joists 18, they transmit point loads from one joist 18 to the adjacent joists 18 by supplying support to the joists 18 in compression or tension. The floor-bridging units 10 add stiffness and rigidity to the floor system. The increase in rigidity and stiffness allows for longer joist spans, shallower joists 18, or wider on-center joists 18, thereby providing for more cost-effective material usage.
The floor-bridging unit 10 is usually constructed by creating the X member 12 from two legs 22 of #2 grade kiln dried spruce 2xc3x973s. The 2xc3x973 are each planed to tolerance, mitered on the ends and dado cut at the center to remove a portion of material from each piece, as shown in FIG. 3. The two dado cut slots 24 are then joined together with glue and staples to form the X member 12 of the floor-bridging unit 10. The xc2xexe2x80x3 Douglas Fir plywood flanges 14 are then glued and nailed to the ends of the X member 12 to form the floor-bridging unit 10, as shown in FIG. 1. Current industry practices are to first plane the 2xc3x973 lumber for the legs 22 and then to cut the lumber to length using a hand operated miter saw. The 2xc3x973 lumber is actually about 1 and xc2xd inches by 2 and xc2xd inches and is planed downed to a consistent 1 and xc2xd inches by 2 and {fraction (7/16)} inches. The lumber is planed because initially the lumber is not a consistent size and needs to be in order to maintain the manufacture of a quality product. Once cut to length, the dado slot 24 is cut into the legs 22 by a saw. Two legs 22 are joined at the dado slots 24 to create a dado joint and form the X member 12. This joint is glued and stapled together. The ends of the joined legs 22 are trimmed to tolerance in a table saw. To make the flanges 14, sheet wood is cut into strips and then into rectangles on a table saw. Glue is then applied by hand to the four ends of the dado joined legs 22 of X member 12. After the glue is applied, the rectangles are positioned onto the ends by hand and nailed in place using a hand operated nail gun.
It is an object of the present invention is to provide a method of mass producing floor-bridging units 10 in an efficient and cost effective manner.
A method of producing the floor-bridging units, which increases production rate of the floor-bridging units. First rough lumber beams are fed through a planer, which planes the lumber to the required consistent size tolerance. The planed lumber is transferred to a cut-off saw to cut the legs. The legs are transferred to a dado machine and a dado slot is cut into the lumber. The legs are transferred to a joining station to form the X member, where the dado slots are joined into a dado joint by gluing and stapling the joint. The X member is transferred to a trimming station to be trimmed. At the same time flanges are being made by cutting sheet lumber in strips and then into rectangles to form the flanges. The flanges are transferred to a nailing jig, while glue is applied to the trimmed ends of the legs of the X members. The X members with the applied glue are transferred to the nailing jig. Finally, the flanges are nailed to the glued ends of the X members and the finished floor-bridging units are transferred to a packaging area.